Newport LDC-3706 Series, User Manual

Page: 122 / 124

December 2019 110 LDC-3706 Series Laser Controller
Two Point Calibration Method
This procedure will work for any linear IC temperature sensor. The accuracy of this procedure
depends on the accuracy of the known temperatures, externally measured. It is used to
determine the zero offset of the device and the gain offset (slope).
1. Allow the LDC-3706 instrument to warm-up for at least one hour. Set the sensor to the
desired sensor type, and RECALL the constants for the particular device to be
calibrated.
2. Select the C
1
parameter. Read and record the value of C
1
. Select the C
2
parameter.
Read and record the value of C
2
.
3. Place the sensor at an accurately known and stable temperature, T
a1
. Connect the
sensor to pins 14 and 15 for the LDC-3736 or LDC-37620 25-pin connector or pins 7
and 8 of the LDC-3726 15-pin connector. Set the LDC-3706 instrument to normal
constant temperature (T mode) operation. Allow the LDC-3706 instrument to stabilize
at the known temperature, T
a1
and read the displayed temperature, T
d1
. Record these
values.
4. Repeat Step 3 for another known temperature, T
a2
, and the corresponding displayed
temperature, T
d2
. The two known temperatures should at the bounds of the intended
operating range. The smaller of the two is intended operating range, the better the
calibration over that same range.
5. Determine the new value of C
1
(C
1n
) and C
2
(C
2n
) from the following calculations.
First determine the intermediate values U and V, where
= and = − ( ∗ )
Then C
1n
and C
2n
can be determined by the following:
= + ( ∗ ) and = ∗
6. Replace C
1
with C
1n
by selecting the C
1
parameter and entering the new C
1n
value.
Replace C
2
with C
2n
by selecting the C
2
parameter and entering the new C
2n
value.